Adjusting and controlling reed relays

ABSTRACT

A process for adjusting and checking reed relays comprises locally heating one of the two switching tongues by a high frequency heating system, and deflecting both switching tongues simultaneously by magnetic force, so that the switching tongue exposed to high frequency heating undergoes a permanent material deformation.

Unite States Beaud 1 June 13, 1972 ADJUSTING AND CONTROLLING REED RELAYS [72] Inventor:

[73] Assignee: l-Iasler A. G., Bern, Switzerland [22] Filed: June 3, 1970 [21] Appl. No.: 43,134

Jean-Louis Beaud, Neuchatel, Switzerland [30] Foreign Application Priority Data June 6, 1969 Switzerland ..8605/69 [52] US. Cl.. ..2l9/7.5, 29/622 [51] Int. Cl. ..H05b [58] Field of Search ..2l9/7.5; 29/622 [5 6] References Cited UNITED STATES PATENTS 2,882,648 4/1959 Hougaard et al ..29/622 UX 3,440,032 4/1969 Cook, Jr. et al ..29/622 X 263,141 8/1882 Edison ..3l6/29 X OTHER PUBLICATIONS IBM T.D.B., Vol. 1l,No. 3, August 1968, Mechanically-Actuated Magnetic Switch by Cuzner and Wallis.

Primary Examiner-J. Vi Truhe Assistant Examiner-Hugh D. Jaeger Att0rney-Michael S. Striker 57 ABSTRACT A process for adjusting and checking reed relays comprises locally heating one of the two switching tongues by a high frequency heating system, and deflecting both switching tongues simultaneously by magnetic force, so that the switching tongue exposed to high frequency heating undergoes a permanent material deformation.

5 Claims, 4 Drawing Figures 1 ADJUSTING AND CONTROLLING REED RELAYS BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to reed relays.

The most important components of a reed relay are the switching tongues or reeds which simultaneously conduct the switching current and the magnetic flux. The air gap of the relay is situated in the area of overlap of these switching tongues. So as to have as low as possible an electric contact resistance at the area of overlap of the switching tongues when the air gap is closed, precious metal is applied on the switching tongues at this point. Gold and rhodium are primarily applied for this purpose, and normally gold is diffused into the material of the tongues by a special treatment.

2. Description of the Prior Art In a known form of embodiment of a reed relay, the metal pins leading ambilaterally through the glass cylinder are firmly joined to their switching tongues by means of a flat connecting spring in each case, and the switching tongues are housed in a sealed glass cylinder filled with protective gas.

When the switching tongues are being fused into the glass cylinder, it must be expected that the switching tongues will not be positioned precisely symmetrical to the longitudinal axis of the glass cylinder or that the close tolerances for the opening width of the air gap will not be maintained.

SUMMARY According to the invention a process for adjusting and checking reed relays having two switching tongues fused into a glass cylinder, comprises locally heating one of the two tongues by means of a high-frequency heating system, and applying magnetic force to deflect both switching tongues simultaneously so that the switching tongue exposed to highfrequency heating undergoes a permanent material deformation.

The'invention also includes a device for the application of the process described above, comprising a high-frequency coil, by means of which the extremity of said one switching tongue adjacent a metal lead-in connected thereto is heated locally, situated outside the glass cylinder of the reed relay, and a three-pole electromagnet, by means of which both switching tongues are deflected, also situated outside the glass cylinder.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows by way of example, an adjusting and checking device sketched in diagrammatical manner only; and

FIGS. 2 to 4 show the essential parts of the device for adjusting and checking the switching tongues, from the left according to FIG. 1, in three different examples of application. Compared to FIG. 1, the individual parts are illustrated to larger scale.

DESCRIPTION OF THE PREFERRED EMBODIMENT As is apparent from FIG. 1, the rays of a source of light 11 are deflected parallel along the optical axis of a lens system 12 and projected to a second lens system 13 which performs an enlargement of the image. By means of a rotatable mirror l4,

the image is projected under 30x magnification on to an image screen 15 facing towards an observer. In this way, it is possible to check on the contact-side extremities of the switching tongues 23a and 23b of a reed relay 20 forming the areas of overlap, and on the air gap between these switching tongues, under considerable enlargement, on the image screen 15.

A rotatable holding device (not shown) for the reed relay 20 is arranged in the area of the parallel light rays, i.e. between the two lens systems 12 and 13. A second stationary holding device carries a heating coil 30 and a three-pole electromagnet 40.

To adjust and check the reed relay 20, the reed relay is inserted vertically into the rotatable holding device, so that the wide side of the switching tongues is positioned parallel to the light rays and the areas of overlap are positioned in the area of these light rays.

The three-pole electromagnet 40 shown dotted only in FIG. I, is in reality arranged at right angles to the optical axis behind the reed relay, in such manner that the middle magnetic pole is situated in the region of the area of overlap and the two outer magnetic poles each act individually on one of the two switching tongues 23a, and 23b respectively.

Since FIGS. 2 to 4 each illustrate a view from the left according to FIG. l, the area of overlap as wellas the air gap of the reed relay 20 are visible in these figures.

The two metal lead ins 22a and 22b of the reed relay 20 lead into the glass cylinder 21 sealed off in vacuum-tight manner. The switching tongues 23a and 23b whereof the free extremities from the area of overlap and the air gap, are firmly joined to the metal lead-ins 22a and 22b by means of flat connecting springs 24a and 24b. The joint between these parts may be made by welding, for example. The high-frequency coil 30 encloses the lower extremity of the glass cylinder 21, as viewed in FIGS. 2 to 4, so that it acts on the flat connecting spring 24b and preponderantly heats only the latter when energized.

So that the area in which the heating coil 30 is effective may be reduced to a localized minimum, the coil consists of a single winding encircling the glass cylinder 21.

The electromagnet 40 also arranged outside the glass cylinder 30 and facing towards the wide side of the switching tongues, has two windings 41 and 42 as well as three magnetic poles 43, 44 and 45. The electromagnet 40 is vertically positioned so that its central pole 44 is situated opposite to the area'of overlap. The magnetic pole 43 is situated opposite to the switching tongue 23a and the magnetic pole 45 is situated opposite to the switching tongue 23b.

If the air gap of a reed relay is to be opened out, the reed relay is inserted into the holding device as illustrated in FIG. 2, the lower switching tongue 23b susceptible to the effect of the heating coil 30 being closer to the electromagnet 40 than the upper switching tongue 23a.

After the reed relay has been inserted, the heating coil 30 as well as the magnet coils 41 and 42 are briefly energized. As soon as the electrical field of the high-frequency coil 30 permeates the connecting spring 24b, the latter is heated very rapidly. At the same time, the switching tongues 23a and 23b are deflected towards the left by the magnetic force of the magnetic poles 43 and 45. The air gap between the two switching tongues 23a and 23b is kept open by the action of the central magnetic pole 44. As soon as the current to the coils 30, 41 and 42 is interrupted, the connecting spring 24a cools down and the switching tongues spring back towards the right. The heating of the connecting spring 24b by means of the high-frequency coil 30 reduces its limit of elasticity to an extend that a permanent material deformation is engendered by the force of the electromagnet 40.

In this method of application of the device, the switching tongue 23b stops at a greater distance from the switching tongue 23a after interruption of the supply of current, i.e. the aperture of the gap is increased. This change can be verified on the image screen 15.

To reduce the air gap of a reed relay, the reed relay is inserted into the holding device as illustrated in FIG. 3. In this case, the lower switching tongue 23b susceptible to the effect of the heating coil 30 is more distant from the electromagnet 40 than the upper switching tongue 23a. If the heating coil 30 and the magnet coils 41, 42 are energized briefly in this position of the reed relay, the connecting spring 24b is heated and the switching tongues 23a and 23b are bent over towards the left. In this case too, the air gap present between the two switching tongues is kept open by the action of the central magnetic pole 44. As soon as the current to the coils 30, 41 and 42 has been interrupted, the connecting spring 24b cools down and the switching tongues 23a and 23b spring back towards the right. Owing to the material deformation engendered in this case in the switching tongue 23b with respect to the connecting spring 2412, the switching spring 23b stops after springing back, at a smaller distance from the switching spring 24a, i.e. the aperture of the air gap is reduced.

If the switching tongues are positioned asymmetrically to the longitudinal axis of the relay in the glass cylinder during production, it is possible by analogous application of the device described above to ensure that these are corrected into the symmetrical position. The insertion into the holding device is performed either with the switching tongue 23a or else the switching tongue 23b facing towards the heating coil 30, depending on the required direction of correction.

These examples of application show the manner in which the mutual position of the switching tongues housed in a glass cylinder sealed off in vacuum-tight manner and filled with protective gas can be changed or corrected by means of the device according to the invention. Short pulses of current, lasting 1 to 2 seconds only, are fed to the coils 30, 41 and 42. The total period of energization respective to the number of current pulses, depends on the magnitude of the correction to be applied. In each case of correction, however, the heating period of the coil is so short and its action is so limited locally that the glass cylinder 21 is not damaged.

FIG. 4 illustrates the manner in which the device according to the invention may be employed to check or inspect the reed relays. In this case, the two magnet coils 41 and 42 are connected in series and the heating coil 30 is switched off. A current pulse through the magnet coils 41 and 42 causes the magnetic polcs43 and 45 to close the air gap, so that the two switching tongues 23a and 23b touch each other in the area of overlap. The parallelism and length of overlap of the switching tongue contacts may be checked on the image screen 15.

I claim:

1. Device for adjusting and checking reed relays having a sealed glass envelope, a pair of metallic lead-ins fused into the material of said envelope and extending into the latter, and a pair of switching tongues in said envelope and each having an end portion conductively connected with one of said lead-ins, said device comprising first means for locally heating said one end portion of one of said tongues from outside said sealed glass envelope so as to render it plastically deformable; and second means operatively associated with said first means for magnetically deflecting said one tongue from the exterior of said sealed glass envelope while said one end portion is in plastically deformable condition, whereby to effect permanent deformation of said one end portion.

2. Device according to claim 1, wherein said first means comprises a high-frequency coil.

3. Device according to claim 2, wherein said second means comprises a three-pole electromagnet.

4. Device according to claim 2, said switching tongues each comprising a main portion and a connecting spring connecting said main portion with the respective lead-in and constituting said one end portion; and wherein said high-frequency coil surrounds said sealed glass envelope in the area of said connecting spring of said one tongue, so as to preponderantly heat said connecting spring thereof. 

1. Device for adjusting and checking reed relays having a sealed glass envelope, a pair of metallic lead-ins fused into the material of said envelope and extending into the latter, and a pair of switching tongues in said envelope and each having an end portion conductively connected with one of said lead-ins, said device comprising first means for locally heating said one end portion of one of said tongues from outside said sealed glass envelope so as to render it plastically deformable; and second means operatively associated with said first means for magnetically deflecting said one tongue from the exterior of said sealed glass envelope while said one end portion is in plastically deformable condition, whereby to effect permanent deformation of said one end portion.
 2. Device according to claim 1, wherein said first means comprises a high-frequency coil.
 3. Device according to claim 2, wherein said second means comprises a three-pole eLectromagnet.
 4. Device according to claim 2, said switching tongues each comprising a main portion and a connecting spring connecting said main portion with the respective lead-in and constituting said one end portion; and wherein said high-frequency coil surrounds said sealed glass envelope in the area of said connecting spring of said one tongue, so as to preponderantly heat said connecting spring thereof.
 5. Device according to claim 2, wherein said high-frequency coil comprises a single winding adapted to accommodate said sealed glass envelope. 